Method of producing alpha gas-purifying material



HNETED STATES trainee PATENT ro enten T v EDWARD .r. MURPHY, orBnooKLYN, NEW YORK, 'AssIe on To run BARTLETT nA WARD oonrrANY,orrAnrnvronn, MARYLAND, A oonronA'rIoN or MARYLAND METHOD OF PRODUCING AGAS-PURIFYlNG MATERIAL Silo Drawing. Application filed December 6, 1923,

My invention relates to the production of a purification medium for theremoval of impurities from gases. More specifically, myinv'entionrelates to the treatment of materials, such as ores,containing as the principal constituent iron .oxide, to confer aon thelatter an increased capacity to remove impurities such as hydrogensulfide from gases.

Various gases such as producer gas, water My gas, coal gas,,illuminatinggas,and fuel gas,

contain as an impurity, hydrogen sulfide. It

is usually necessary and desirable before using these gases to removethe hydrogen sulfide. It has been proposed to accomplish the same 5 bypassing the gases through a purification medium such as naturaloccurring or artifically produced iron oxide after it has been subjected to treatment to modify its physical and chemical characteristicsAs far as I am aware, these original products are deficient in theircapacity to remove hydrogen sulfide.

I have found that by reducing ores, for

., example those found in the Lake Superior region, to a ,very finestate of division and thereafter heating the same as hereinafter setforth, the capacity of the iron'oxide to remove hydrogen sulfide isgreatly increased.

It is desired to point out that the fineness of the material and theheat treatment both contribute'towards increasing the capacity of theoxide to remove hydrogen sulfide. For

the best results it has been-found that the I oxide should be reduced totwo hundred mesh and then heated preferably to between 200 and 400 C.llronoxide which has been reduced to one hundred mesh and heated to 200C. showsa fair removal capacity. How- A ever, at 300 C. this is greatlyincreased and at 400 C. the capacity is still greater. Iron oxide whichhas been reduced to two hundred mesh and heated to between 300 C. and400 C. shows a still greater capacity for the reso necessary, to such amoisture content as to terial is passed through a kiln, preferably of tocause fires when used in dry purifiers.

moval: of hydrogen sulfide than that which Serial No. 679,007. RenewedDecember 26, was.

permit convenient feeding to a pulverizer where it is crushed andpulverized to about two hundred mesh; v Any suitable pulverizer may beused. Thereafter, the reduced mathe rotary type, and heated. to between300 C. and 400 C. for a period sufiicient to confer upon the ironoxidewhat may be termed super-activity. Obviously the time of the heattreatment will vary somewhat with the different ores. When using certainores, from the Lake Su erior region, heat treatmentfor a period 0 fiveminutes is sat- 'isfa-ctory. The ore is Withdrawn from the kiln, allowedto cool, and slightly. dampened. with water. -The ore which may bestored until used, is adapted for use in liqfiid purification of gases.For example, a 3% suspen- Sion of the ore' in water furnishes an admirable gas purification medium. If dry purification material isdesirable, it is only necessary to reduce to one hundred mesh, as thematerial ground more finely would tend The following results wereobtained by re- 35 ducing iron oxide to the mesh stated and thensubjecting the resulting product to heat treatment. Kunbergersmethod wasused for determining the absorption of hydrogen sul phide. This consistsof passing hydrogen sulphide gas through a weighed quantity of thetreated ore mixed with sawdust and noting the percentage of absorptionof hydrogen sulphide by weight.

' Buffalo 076,,LOJ06 SuperiorDistriht-Iron om'de moo 65.15%

Temp. of treatment-heating- 200 0. 300 C. (mln.)

Not 400 C. heated 8 5 5 Per cent Per cent Per cent Per cent Fouling No.1-1190 absorbed 11. 16 97 25.53 Fouling N0. 2-HgS absorbed...- 20.82 31.26 29. 74 28. Fouling No. 3-H5S ebsorbed 22. 54 25. 21 32. 03 33. 76Fouling N0. 4-13 8 absorbed.- 2A. 13 31. 92 35. 43 34. 58

Total H absorbed 78.85 108. 35 119. l 122. 67 1mg Beamcr are, LakeSuperior District- Iron ozm'de 76.73%

FOULING TESTS [Material reduced to 100 mesh] 0 Temp. oftreatmentheating(min.) g g Per cent Per cent Per-cent Fouling No. 1-H2Sabsorbed 2. 54 8 39 14. 38

Per cent Per cent Per cent Fouling No. 1H,s absorbed 2o.

Fouling No. z-ms absorbed" 4. 23 14134 24. 59 Fouling No. 3-1318absorbed" 18. 8O 25. 57

Total H18 absorbed 41. e5 71. 01

From the above it is clear that by heating ores. containing iron oxidewhich have been reduced to one hundred mesh, they become more active intheir capacity to remove hydrogen sulfide.

The following tests show the efiect of reducing to. two hundred mesh andsubjecting the ore to heat treatment:

Buffalo oreI 1-on wide 65.15%

FOULING TESTS [Material reduced to 200 mesh] Not 400 C.

Temp. 02 treatment-time of heating in minutes heated 5 5 Per cent Percent Per cent i 2 .43 3 .64

Fouling No. 1-H2S absorbed"--. 4 9 47. 56 Fouling No. 2-1328 absorbed.32. 21 44. 10 31. 80 Fouling N0. 3-H1S absorbed, 31.82 36. 89 31. 05Fouling No. 4-H=S absorbed 21. 37 23. 73 30. 21

Total Has absorbed 109. 83 144. 36 140. 62

The results set forth in the above table indicate the importance of finegrinding and subsequent heat treatment on the activity of the ore. Asfurther indicating that heat treatment alone is not sufficient to conferupon the'ore a high capacity to remove hy- Elrogen sulfide, thefollowing results are set orth:

Buffalo ore-Jron oande 65.15%

FOULING TESTS [Material reauced to 20 mesh] Temp. 02 treatment-time ofheatingin Not minutes heated 5 5 Per ce-m Per cent Per cent 11. L8 15.8G 14. 8G

Fouling No. 1412s absorbed Fouling No. 2--HzS absorbed In comparisonwith mamrials heretofore used for gas purification my material may betermed superactive, and it is intended by the use of this term in theclaims to distinguish from the materials of ordinary activity ,wellknown in the art.

What is claimed is: 1. The method of preparing a gas purificationmaterial super-active in its capacity to remove hydrogen sulfide fromgases comprising reducing to two hundred mesh a material containing asits principal constituent iron oxide, and heating to at least 200 C. toincrease the activity of the material.

2. The method of preparing a gas purification material super-active inits capacity to remove hydrogen sulfide from gases comprising reducingto two hundred mesh a material containing as its principal constituentiron oxide, and heating to between 200 C. and 400 C,

3. As a new product, a gas purification medium comprising a materialcontaining as its principal constituent iron oxide, which has beenreduced to two hundred mesh and heated to above 200 (1, and an aqueouscarrying-vehicle therefor. 1

4. As a new product, a gas purification medium comprising a materialcontaining as its principal constituent iron oxide, which has beenreduced to two hundred mesh and heated to 400 (1., and an aqueouscarryingvehicle therefor.

In testimony whereof I have signed my name to this specification.

EDWARD J. MUURPHY.

